• INCLUSION CRITERIA:

HEALTHY VOLUNTEERS:

Healthy volunteers are between the ages of 21 and 65 years.

PATIENTS:

Patients will have clinically documented Tourette's syndrome or chronic motor tic disorder as defined by DSM-IV-TR and evaluation of tic severity using the Yale Tic Scale. This criterion will be established by preliminary screening in the NINDS Movement Disorders Outpatient Clinic. Regarding co-morbid disorders such as ADHD and OCD, we will accept a mild degree of ADHD and mild to moderate degree of OCD. These disorders will be established by a psychiatrist using below listed scales and criteria.

Structure Clinical Interview for (DSMIV SCID) will be administered to all subjects to ensure that strict DSM-IV criteria for Tourette Syndrome have been met and to assess for possible comorbid psychiatric disorders.

Given the high rate of comorbidity of Obsessive Compulsive Disorder (OCD) and Attention Deficit/Hyperactivity Disorder (ADHD) in Tourette's syndrome, it may not be possible to exclude persons with these disorders. Hence, only those with no more than mild to moderate severity of symptoms will be accepted into the study. This will be ascertained using the following instruments and their respective cut-off scores:

Y-BOCS (Goodman et al, 1989) a 10 item scale with a range of 0 - 4 and maximum possible score of 40 (0-7: subclinical; 8 - 15: mild; 16 -23: moderate; 24 - 31 severe; 32 - 40: extreme). Inclusion criteria: 23 or below.

ADHD Behavior Checklist for Adults (Barkley, 1995, Murphy and Barkley, 1995): An 18 Item checklist with 9 Inattention items and 9 Hyperactive/impulsive items ranging 0 - 3 (0: never or rarely 1: sometimes 2: often and 3: very often ). Items answered often or very often are scored as present. With age, the threshold criterion for presence of ADHD become lower and is currently accepted as follows:

Age Range; Inattention Items; Hyperactive and Impulsive Items respectively:

21-29 years; 4 of 9; 5 of 9

30-49; 4 of 9; 4 of 9

50 and over; 3 of 9; 3 of 9

Inclusion Criteria:

Age Range; Inattention Items; Hyperactive and Impulsive Items respectively:

21-29 years; 3 or below; 4 or below

30-49; 3 or below; 3 or below

50 and over; 2 or below; 2 or below

EXCLUSION CRITERIA IN HEALTHY VOLUNTEERS AND PATIENTS:

The following subjects will be excluded from the study:

1. Subjects younger than 21 or older than 65 years, as EEG studies have shown findings to vary with neurodevelopment and age.
2. Subjects with 1) major depression, 2) bipolar disorder, or 3) psychotic disorder. Such coexisting neuropsychiatric disorders may lead to unnecessary confounds of the data.
3. Subjects taking benzodiazepines, anti-depressant or neuroleptic medications (such medications are known to affect EEG and may thus confound data)
4. Subjects with major acute or chronic illness (experimental setting may be unnecessarily uncomfortable or unpleasant)